1. Field of Invention
This invention relates to photographic film and is particularly directed to an improved cartridge for facilitating the loading and handling of photographic film and for increasing the flexibility and versatility of cameras using film cartridges.
2. Prior Art
It has long been known, in the photographic field, that packaging film in cartridges has numerous advantages over conventional reels or cassette-packaged film. Both reels and cassette-packaged film require that the leading end of the film be properly connected to the film advance mechanism. This is often a difficult procedure or one wherein the film can easily become unseated after positioning, with the result that many photographic opportunities are lost and frequently an entire film is wasted. With cartridge film, the film is loaded by simply dropping the cartridge into the camera. The cartridge cannot be loaded improperly, so that the foregoing problems are overcome. Furthermore, photographers often desire to change films, for example, to permit taking color and black-and-white pictures of a given subject. With reel of cassette-packaged film, such film changes are difficult or impossible to accomplish and require the use of separate cameras for each type of film or risk possible loss of an entire film in trying to make such a substitution. In contrast, film cartridges can readily be removed and replaced at any time, with a maximum loss of only one frame. Thus, the cartridge-packaged film provides greater versatility and flexibility for the photographer.
In spite of these advantages, cartridge-packaged film has never gained acceptance with professional and advanced amateur photographers. One reason for this lack of acceptance has been the fact that these photographers usually prefer 35 millimeter film because of the uniformly high quality of such film and because this size film provides a relatively large exposure area with a camera which is relatively small and convenient to transport and use. Originally, however, 35 millimeter film was developed for movie cameras. As a result, the edges of the film are generally perforated to accommodate the sprockets of movie cameras and projectors and many of the manufacturers of 35 millimeter cameras have designed film advancing mechanisms which utilize these perforations.
Obviously, the space occupied by these perforations substantially reduces the area of the film which is available for photographic exposure. However, because the useful area of the film is superior to that of other available film and because the manufacturers have produced an ever increasing range of cameras and lenses designed for 35 millimeter film, the photographers have accepted the perforations as a necessary compromise. Originally, use of 35 millimeter cameras required a high level of skill and knowledge of the interrelation of film speeds, shutter speeds, aperture settings, light levels, etc. Consequently, only professional or serious amateur photographers attempted to use these cameras.
Recently, the introduction of electronics and miniaturization into camera design and manufacture has greatly reduced the level of skill required to use 35 millimeter cameras and many so-called "point-and-shoot" cameras are available using 35 millimeter film. Unfortunately, these cameras still use reel or cassette film which presents the loading and advancing problems discussed above. Currently, much research is being devoted to attempts to mechanize film loading and advancement mechanisms. However, no satisfactory solution has been developed so far and the complexity of the automatic film loading and advancing mechanisms have significantly increased the complexity of these cameras and the cost of producing and maintaining them.
Numerous attempts have been made, heretofore, to develop cassettes for 35 millimeter film to overcome these problems of film loading and advancing. Unfortunately, none of the prior art devices have been entirely satisfactory or have provided sufficient advantages to persuade manufacturers to adopt the cassettes or to persuade photographers to demand them. Most of the prior art film cassettes have been capable of use only with a specific camera which was designed to use that particular cassette and the advantages offered by the prior art cassettes have not been sufficient to persuade other camera manufacturers to adapt to them or to persuade serious photographers to demand them. A search in the United States Patent Office has revealed the following patents:
______________________________________ U.S. Pat. No. INVENTOR ISSUED ______________________________________ 3,347,142 K. Steisslinger Oct. 17. 1967 3,426,666 S. Nagata Feb. 11, 1969 3,528,356 J. Eagle Sep. 15, 1970 3,593,635 H. Servetnick July 20, 1971 ______________________________________
The patents to Nagata and Eagle each disclose film cartridges which are for use only with specific cameras which are also disclosed in these patents. The patents to Steisslinger and Servetnick relate only to film cartridges. All of these references seek to overcome the film loading problems discussed above. However, none of these patents provides any additional incentive for manufacturers to adapt their cameras to use film cartridges, nor do they provide any additional incentive for photographers to demand their use. Thus, none of the prior film cartridges has been entirely satisfactory.